Chronic cholestatic disorders in the adult

Many hepatobiliary diseases can result in cholestasis. The main causes of chronic cholestasis in adults are primary biliary cirrhosis, which is characterized by portal triad inflammation and segmental necrosis of interlobular bile ducts, and primary sclerosing cholangitis, in which the intra and/or extrahepatic bile ducts undergo inflammation and fibrosis. The diagnosis is based on the presence of evidence of cholestasis and of symptoms specific for each condition. A number of drugs, sarcoidosis, total parenteral nutrition, chronic liver transplant rejection, and graft-versus-host disease can also cause chronic cholestasis. The treatment of these conditions has benefited greatly from rational use of ursodeoxycholic acid.     

Expression of Bcl-2 familial proteins is reduced in small bile duct lesions of primary biliary cirrhosis

In primary biliary cirrhosis, biliary epithelial cell death by apoptosis results in progressive bile duct loss. We examined immunohistochemically 4 apoptosis-regulating bcl-2 familial proteins (bcl-2, mcl-1, bcl-X, and bax) in the biliary epithelium in 19 cases of primary biliary cirrhosis. Ten cases of chronic hepatitis C, 9 cases of extrahepatic biliary obstruction, and 10 cases of normal liver were used as a control. Bcl-2 and mcl-1 are inhibitors of apoptosis, bcl-X, probably bcl-XL in biliary epithelial cells, an inhibitor, and bax, a promoter of apoptosis. First, we clarified the distribution of bcl-2 familial proteins on the intrahepatic biliary tree in normal livers. Bcl-2 was detected in the interlobular bile ducts and bile ductules, but not in the large and septal bile ducts in all cases examined. Mcl-1, bcl-X, and bax were diffusely detectable at the any level of the intrahepatic biliary tree, with a staining pattern that was diffuse and cytoplasmic. This distribution pattern was preserved in extrahepatic biliary obstruction. Bcl-2 expression was lost or markedly reduced in the damaged interlobular bile ducts in primary biliary cirrhosis, whereas the reduction was only focal or mild in the bile ducts with hepatitis-associated damage in chronic hepatitis C. Expression levels of mcl-1, bcl-X, and bax were similarly reduced to that of bcl-2 in these 2 diseases. These findings suggest that bax is not important as a proapoptotic factor in the damaged bile ducts and that downregulation of bcl-2 and mcl-1, and probably that of bcl-XL, leads to a decrease in the threshold of apoptosis and increase in the vulnerability to apoptotic stimuli in these bile ducts, followed by the progressive apoptotic loss of interlobular bile ducts, in primary biliary cirrhosis.     

The role of liver biopsy in evaluating acute allograft dysfunction following liver transplantation: a clinical histologic correlation of 34 liver transplants

One hundred six liver biopsy specimens from 34 orthotopic liver transplant (OLT) patients were examined and the histologic findings correlated with the clinical course of the patients to determine if specific morphologic patterns were associated with specific causes of acute allograft dysfunction. The principle causes of allograft injury in these patients appeared to be acute rejection and ischemic injury, with rarer cases of viral infection and biliary obstruction. Graft rejection causing transient liver dysfunction was associated with a mixed inflammatory infiltrate in the portal tracts and involving the interlobular bile ducts. Rejection resulting in severe, persistent dysfunction was associated with destruction and loss of the interlobular bile ducts or portal inflammation, followed by acute centrilobular hepatocyte necrosis. Ischemic liver injury was characterized by hepatocyte ballooning and/or hepatocyte necrosis. Ischemic injury causing transient graft dysfunction demonstrated focal, limited areas of hepatocyte necrosis or transient centrilobular hepatocyte ballooning. Severe ischemic injury resulting in persistent dysfunction caused diffuse hepatocyte necrosis or centrilobular ballooning followed by centrilobular hepatocyte loss and severe cholestasis with evidence of bile duct epithelial injury. The histologic patterns observed were not pathognomonic; radiologic studies, bile cultures, and other laboratory tests were necessary to rule out biliary or vascular obstruction and bacterial cholangitis. However, liver biopsies, especially serial biopsies, were helpful in suggesting the probable cause of liver dysfunction and in predicting subsequent allograft recovery or failure.     

Bile ductal and ductular changes of the livers in the renal allografted patients

Nine liver biopsies from six renal allografted patients suffering from liver injury were examined by light and electron microscope and immunostaining. The patients had never been on liver dysfunction prior to renal transplantation and after renal transplantation had been administered azathioprine continuously. These patients had shown HBs antigen negative sera. Three of these patients restored normal liver function after withdrawal of azathioprine. Accordingly, the liver diseases of the three were supposedly caused by azathioprine. The liver biopsies of six patients were histologically diagnosed as follows: chronic active hepatitis with severe cholestasis (1 patient), liver cirrhosis with cholestasis (1 patient), acute hepatitis (1 patient), and mild hepatitis (3 patients). The common pathological findings of six patients were degeneration of interlobular bile ducts and ductules, as well as degeneration of liver cells, and mild to moderate inflammatory cell infiltration of portal tracts and sinusoids. The degeneration of bile ductal and ductular cells were classified into two types: light microscopical finding showed vacuolar or eosinophilic cytoplasm and electron microscopic compatible findings showed hydropic cytoplasm scant of free ribosome and organelles, or dense cytoplasm rich in free ribosome and degenerated organelles. The basement membranes of interlobular bile ducts and ductules were always preserved.     

BILE DUCTAL AND DUCTULAR CHANGES OF THE LIVERS IN THE RENAL ALLOGRAFTED PATIENTS

Nine liver biopsies from six renal allografted patients suffering from liver injury were examined by light and electron microscope and immunostaining. The patients had never been on liver dysfunction prior to renal transplantation and after renal transplanatation had been administered azathioprine continuously. These patients had shown HBs antigen negative sera. Three of these patients restored normal liver function after withdrawal of azathioprine. Accordingly, the liver diseases of the three were supposedly caused by azathioprine. The liver biopsies of six patients were histologically diagnosed as follows: chronic active hepatitis with severe cholestasis (1 patient), liver cirrhosis with cholestasis (1 patient), acute hepatitis (1 patient), and mild hepatitis (3 patients). The common pathological findings of six patients were degeneration of interlobular bile ducts and ductules, as well as degeneration of liver cells, and mild to moderate inflammatory cell infiltration of portal tracts and sinusoids. The degeneration of bile ductal and ductular cells were classified into two types: light microscopical finding showed vacuolar or eosinophilic cytoplasm and electron microscopic compatible findings showed hydropic cytoplasm scant of free ribosome and organelles, or dense cytoplasm rich in free ribosome and degenerated organelles. The basement membranes of interlobular bile ducts and ductules were always preserved.     

Apoptosis in the human liver during allograft rejection and end-stage liver disease

The contribution of apoptosis (programmed cell death) to cellular damage in human liver disease is unknown. Using the in situ DNA end labelling method (ISEL), evidence was sought of programmed cell death (PCD) in liver tissue from patients with various liver diseases. In particular, the study aimed to determine whether PCD is involved in either the loss of interlobular bile ducts (vanishing bile duct syndrome—VBDS) or the perivenular hepatocyte drop-out, both of which are characteristic of irreversible graft rejection. Large numbers of apoptotic hepatocytes were found in pervenular areas in tissues taken from patients with chronic graft rejection. Significant hepatocyte apoptosis, was not seen in long-term stable allografts, primary biliary cirrhosis, cholestasis, paracetamol-induced fulminant hepatic failure, or fulminant hepatic failure of indeterminate origin (non-A, non-B, non-C hepatitis). Bile ducts rarely stained positively, but mononuclear cells present in the post-transplant tissues were frequently positive, showing nuclear or cytoplasmic staining. The presence of cytoplasmic staining suggested that some mononuclear cells had ingested apoptotic DNA from other cellular sources. PCD may thus contribute to the perivenular hepatocyte loss in chronic rejection. The absence of ductular epithelial cell staining suggests that PCD is not involved significantly in the bile duct loss of VBDS. Furthermore, apoptosis of monomuclear cells implies that PCD may be involved in regulating the inflammatory cell infiltration of graft rejection.     

Histological features of sclerosing cholangitis in patients with chronic ulcerative colitis.

Primary sclerosing cholangitis was diagnosed radiologically in 16 of 681 patients (2.2%) with chronic ulcerative colitis in a follow up study at the gastroenterology unit in Oxford. On the basis of established histological criteria, the liver biopsy was considered diagnostic in only half of the cases. The histological findings in these cases were therefore reassessed to determine whether the accuracy of biopsy diagnosis could be improved. The most common specific histological feature was periductal concentric fibrosis of small interlobular bile ducts, even in the absence of inflammation. Other common features were bile ductular proliferation associated with diminution or absence of interlobular bile ducts. Degeneration of bile duct epithelium and diffuse infiltration of portal tracts by mononuclear cells and polymorphonuclear leucocytes were accompanying features. Piecemeal necrosis without rosette formation was found in about half the biopsies. When all these features were considered together a biopsy diagnosis of primary sclerosing cholangitis was established in 14 of 16 cases.     

Acute cholangitis and pancreatitis associated with sulindac (clinoril)

A 68-year-old man without previous hepatobiliary or pancreatic disease was admitted after five attacks of nausea, vomiting, abdominal pain and high fever. Laboratory investigations indicated cholestatic liver disease and pancreatitis. For 1.5 years the patient had occasionally been taking a non-steroidal anti-inflammatory drug, sulindac (clinoril, MSD, New York), for osteoarthritis. On suspicion of a drug-associated disease, a rechallenge experiment was performed with sulindac. Five hours after drug administration symptoms recurred. There was a pronounced increase in serum alkaline phosphatase and amylase. A liver biopsy 3 d later showed portal tract inflammatory infiltration and abnormal interlobular bile ducts with degeneration and necrosis of the epithelium and neutrophilic infiltration of the ducts. Sulindac-induced cholangitis has not been described previously. The pathogenetic mechanism is considered to be an immunoallergic idiosyncratic reaction to the active metabolite of sulindac absorbed by the bile duct epithelium. The lesion is apparently reversible.     

Ultrastructural localisation and size distribution of collagen fibrils in Glisson's sheath of rat liver: implications for mechanical environment and possible producing cells

The ultrastructure and size distributions of collagen fibrils in Glisson's sheath were investigated in the rat liver to analyse the mechanical environment around the fibrils and their possible cells of origin. Glisson's sheath was found to contain 2 populations of collagen fibrils with different diameters and distinct localisations, namely fibroblast‐associated and bile epithelium‐associated. Fibroblast‐associated collagen was composed of fibrils arranged in bundles and constituted the majority of the collagen in Glisson's sheath. Bile epithelium‐associated collagen was represented by small dispersed groups of fibrils just beneath the basement membrane of the bile duct. The basement membrane of the bile duct was frequently reduplicated into a few or as many as 10 layers of laminae densae, with scattered collagen fibrils between these laminae. The diameters of the fibrils of both groups of collagen increased in relation to the calibre of the bile duct, whereas at any given place in Glisson's sheath bile epithelium‐associated collagen fibrils had a smaller diameter compared with those of the fibroblast‐associated fibrils. The increment in fibril diameter along the bile duct is considered to be correlated with the increase in mechanical stress acting on Glisson's sheath. The difference in diameter between the 2 populations as well as the incorporation of fibrils between the laminae densae of the basement membrane of the bile duct supports the view that the bile epithelium‐associated collagen is produced by the epithelial cells of the bile duct, thus having a different origin from that of fibroblast‐associated collagen. These findings provide the first evidence that the epithelial cells of the interlobular bile duct produce fibril‐forming collagen. Furthermore, it is suggested that cholestasis stimulates the epithelial cells of interlobular bile duct to increased synthesis of fibril‐forming collagen that is also produced by these cells under physiological conditions.     

EXPRESSION OF β2-MICROGLOBULIN ON INTERLOBULAR BILE DUCTS IN PRIMARY BILIARY CIRRHOSIS AND OTHER HEPATOBILIARY DISEASES

Expression of β-microglobulin, a reliable marker of HLA Glass I, on the interlobular bile ducts (bile ducts) was surveyed using an immunoperoxidase method in paraffin sections of specimens from patients with a variety of hepatobiliary diseases. Normal bile ducts showed negativity or weak cytoplasmic positivity in normal as well as diseased livers. On the other hand, abnormal bile ducts showing degenerative or proliferative changes in primary biliary cirrhosis and graft-versus-host disease revealed enhanced expression of this protein, suggesting that these damaged bile ducts might be more susceptible to T cell-mediated immune attack in these immunologic diseases. However, enhanced expression of this protein was also similarly found on abnormal bile ducts in several nonimmunologic biliary diseases Including extrahepatic biliary obstruction. Enhanced expression of this protein on the interlobular bile ducts may therefore be an epiphenomenon secondary to different primary pathologic events in the biliary tree, such as immunologic and nonimmunologic processes. ACTA PATHOL JPN 38 : 853∼860, 1988.     

A HISTOPATHOLOGICAL STUDY OF THE LIVER IN PARAQUAT POISONING: –An Analysis of Fourteen Autopsy Cases with Emphasis on Bile Duct Injury–

Fourteen autopsy cases of paraquat poisoning were studied. Seven of the eight patients who died within 4 days after the ineestion of paraquat showed hepatocytic injury, and three of them revealed bile duct injury. Hepatocytlc injury was similar to that of carbon tetrachloride intoxication. Bile duct injury consisted of epithelial changes of the bile ductules and bile ducts. Cholestasis in the bile ducts was produced by the injury. The affected blle ductules and ducts had hydropic and necrotic epithelium, associated with the infiltration of neutrophils and histiocytes in the lntraductal and periductal tissues. The severity of bile duct injury increased gradually from the bile ductules to the septal bile ducts. The extrahepatic billary tract showed the same injury as the septal bile ducts in one case. It is considered that bile duct injury was produced by a direct corrosive effect of paraquat. Five of the six patients who survived more than 8 days revealed intrahepatic cholestasis, the pathogenesis of which was not clearly understood.     

Expression of beta 2-microglobulin on interlobular bile ducts in primary biliary cirrhosis and other hepatobiliary diseases

Expression of beta 2-microglobulin, a reliable marker of HLA Class I, on the interlobular bile ducts (bile ducts) was surveyed using an immunoperoxidase method in paraffin sections of specimens from patients with a variety of hepatobiliary diseases. Normal bile ducts showed negativity or weak cytoplasmic positivity in normal as well as diseased livers. On the other hand, abnormal bile ducts showing degenerative or proliferative changes in primary biliary cirrhosis and graft-versus-host disease revealed enhanced expression of this protein, suggesting that these damaged bile ducts might be more susceptible to T cell-mediated immune attack in these immunologic diseases. However, enhanced expression of this protein was also similarly found on abnormal bile ducts in several nonimmunologic biliary diseases including extrahepatic biliary obstruction. Enhanced expression of this protein on the interlobular bile ducts may therefore be an epiphenomenon secondary to different primary pathologic events in the biliary tree, such as immunologic and nonimmunologic processes.     

Histological changes of bile duct in experimental graft-versus-host disease across minor histocompatibility barriers. I. Light microscopic and immunocytochemical observations

Graft-versus-host disease (GVHD) across minor histocompatibility antigens was developed in mice and the bile duct lesions were surveyed for up to 7.5 months after spleen and bone marrow cell transplantation. Lymphoid cell infiltration was evident by day 3, reached maximum at 2 weeks, then reduced gradually and persisted during the observation period. Fibrous expansion of the portal tracts paralleled with the time after transplantation, but none of the cases progressed into liver cirrhosis. The infiltrates abutted the interlobular and septal bile ducts and distorted their appearance with a frequent infiltration of mononuclear lymphoid cells into the duct epithelial layer. The duct epithelium showed a variety of degenerative and hyperplastic changes, including nuclear enlargement with anisonucleosis, nuclear pyknosis, cytoplasmic and nuclear darkness, cytoplasmic vacuolization, focal epithelial dropout, formation of apoptotic bodies, and micropapillary infolding. Disappearance of the bile ducts and formation of granuloma around the bile ducts were not seen. Immunocytochemical study revealed the exclusive preponderance of helper/inducer T cells in the portal infiltrates and marked expression of I-A antigen on the bile duct epithelium in GVHD mice. These results suggest that immunological mechanisms by helper/inducer T cells against minor histocompatibility antigen on bile duct epithelium in association with class II molecules of MHC are important in the pathogenesis of the bile duct lesions. A putative role of such lymphocytes is discussed.     

Mesenchymal hamartoma of the liver--an autopsy case with serial sections and some comments on its pathogenesis.

An autopsy case of mesenchymal hamartoma of the liver was reported and from the macroscopical observation and serial sections of the tumor the following findings were found: (1) macroscopically the tumor is supplied by only one large triad, (2) in the tumor hepatic lobular structure is fundamentally preserved and prolifereated bile ducts with surrounding fibrosis and many bile thrombi are mainly elongated and dilated Hering's canals, (3) the cysts connect with dilated interlobular bile ducts, (4) there are two portions, where connection of bile ducts is incomplete, that is, from Hering's canals to interlobular bile ducts and from interlobular ducts to large ducts in the large triad of (1), (5) almost all portal veins in the large triad of (2) are stenosed or obliterated by loose intimal fibrosis. From these findings it is considered that intrahepatic bile duct obstruction resulting in regional biliary cirrhosis is the fundamental process of this disease, and in addition the role of hemodynamic disturbance was discussed.     

Cytological analysis of choledochal mucosa in acute cholangitis in patients with mechanical jaundice

Changes in bile ducts in cholestasis are characterized by activation of proliferation and hypertrophy of cholangiocytes and degenerative and necrobiotic changes in ductal epithelium. Long-term cholestasis led to massive necrosis of cholangiocytes. Inflammatory changes in the choledochal mucosa were most pronounced in patients with choledocholithiasis.     

MESENCHYMAL HAMARTOMA OF THE LIVER – AN AUTOPSY CASE WITH SERIAL SECTIONS AND SOME COMMENTS ON ITS PATHOGENESIS

An autopsy case of mesenchymal hamartoma of the liver was reported and from the macroscoplcal observation and serial sections of the tumor the following findings were found: (1) macroscopically the tumor is supplied by only one large triad, (2) in the tumor hepatic lobular structure is fundamentally preserved and proliferated bile ducts with surrounding fibrosis and many bile thrombi are mainly elongated and dilated Hering's canals, (3) the cysts connect with dilated interlobular bile ducts, (4) there are two portions, where connection of bile ducts is incomplete, that Is, from Hering's canals to interlobular bile ducts and from interlobular ducts to large ducts in the large triad of (1), (5) almost all portal veins in the large triad of (2) are stenosed or obliterated by loose intimal fibrosis. From these findings it is considered that intrahepatic bile duct obstruction resulting in regional biliary cirrhosis is the fundamental process of this disease, and in addition the role of hemodynamic disturbance was discussed.     

Loss of intrahepatic bile ducts: an important feature of familial hemophagocytic lymphohistiocytosis

Familial hemophagocytic lymphohistiocytosis (FHL) is a rare, fatal disorder of early infancy. We report two siblings with FHL whose symptoms were dominated by hepatic failure. Both presented with sudden-onset fever and hepatosplenomegaly with progressive abnormalities of clinical biochemistry indices of liver function. One died of hepatorenal failure. The other underwent liver transplantation. Autopsy and explant liver displayed portal and periportal infiltrates of T lymphocytes and histiocytes; an activation of the hepatic mononuclear phagocytic system with focal hemophagocytosis; and almost complete loss of interlobular bile ducts. Paucity of bile ducts dominated in a pre-transplant liver biopsy specimen (and transiently obscured the diagnosis of FHL). Disease recurred in the allograft, again with lymphohistiocytic infiltration and destruction of interlobular bile ducts. Consequently the patient underwent haploidentical peripheral stem cell transplantation. This patient is alive 5 years later. Loss of bile ducts may be an important feature of hepatic involvement by FHL.     

HISTOLOGICAL CHANGES OF BILE DUCT IN EXPERIMENTAL GRAFT-VERSUS-HOST DISEASE ACROSS MINOR HISTOCOMPATIBILITY BARRIERS

Graft-versus-host disease (GVHD) across minor histocompatibility antigens was developed in mice and the bile duct lesions were surveyed for up to 7.5 months after spleen and bone marrow cell transplantation. Lymphoid cell infiltration was evident by day 3, reached maximum at 2 weeks, then reduced gradually and persisted during the observation period. Fibrous expansion of the portal tracts paralleled with the time after transplantation, but none of the cases progressed into liver cirrhosis. The infiltrates abutted the interlobular and septal bile ducts and distorted their apperance with a frequent infiltration of mononuclear lymphoid cells into the duct epithelial layer. The duct epithelium showed a variety of degenerative and hyperplastic changes, including nuclear enlargement with anisonucleosis, nuclear pyknosis, cytoplasmic and nuclear darkness, cytoplasmic vacuolization, focal epithelial dropout, formation of apoptotic bodies, and micropapillary Infolding. Disappearance of the bile ducts and formation of granuloma around the bile ducts were not seen. Immunocytochemical study revealed the exclusive preponderance of helper/ inducer T cells in the portal infiltrates and marked expression of I-A antigen on the bile duct epithelium in GVHD mice. These results suggest that immunological mechanisms by helper/inducer T cells against minor histocompatibility antigen on bile duct epithelium in association with class II molecules of MHC are important in the pathogenesis of the bile duct lesions. A putative role of such lymphocytes is discussed.     

Primary biliary cirrhosis

Primary biliary cirrhosis is an autoimmune chronic cholestatic liver disease of unknown cause that usually affects middle-aged women. It is characterized by inflammatory destruction of the interlobular and septal bile ducts, which leads to chronic cholestasis and cirrhosis. The diagnosis should be considered in the setting of elevated alkaline phosphatase, immunoglobulin M level and the presence of antimitochondrial antibody in serum. Ursodeoxycholic acid is the only medication of proven benefit for these patients. Liver transplantation is only therapeutic option for patients who have end-stage disease.     

Functional Anatomy of Normal Bile Ducts

The biliary tree is a complex network of conduits that begins with the canals of Hering and progressively merges into a system of interlobular, septal, and major ducts which then coalesce to form the extrahepatic bile ducts, which finally deliver bile to the gallbladder and to the intestine. The biliary epithelium shows a morphological heterogeneity that is strictly associated with a variety of functions performed at the different levels of the biliary tree. In addition to funneling bile into the intestine, cholangiocytes (the epithelial cells lining the bile ducts) are actively involved in bile production by performing both absorbitive and secretory functions. More recently, other important biological properties restricted to cholangiocytes lining the smaller bile ducts have been outlined, with regard to their plasticity (i.e., the ability to undergo limited phenotypic changes), reactivity (i.e., the ability to participate in the inflammatory reaction to liver damage), and ability to behave as liver progenitor cells. Functional interactions with other branching systems, such as nerve and vascular structures, are crucial in the modulation of the different cholangiocyte functions. Anat Rec, 291:653–660, 2008. © 2008 Wiley‐Liss, Inc.